Scanning devices, also known as scanners, have become popular peripherals. A scanning device may be used to obtain an electronic version of a non-electronic image. For instance, a home user may scan a hardcopy of a photograph so that the user can email the resulting electronic version of the photo to friends and family. As another example, business users may scan hardcopies of documents so that electronic versions of the documents can be maintained.
Scanning devices typically employ one or more light-emitting units and a detector. The light-emitting units emit light on a portion of the image to be scanned. The detector detects the reflected light from the portion of the image. This process is repeated over the entire image. When the detector has detected reflected light from all the portions of the image, an electronic version of the media can then be constructed.
A color scanning device usually uses light-emitting units corresponding to the colors of a color space, such as red, green, and blue light-emitting units corresponding to the colors red, green, and blue of the red-green-blue (RGB) color space. The light-emitting units separately and successively emit their colored lights onto a portion of the image, which the detector detects. The detected intensities of the individual colors of the color space for the image are then used to construct an electronic version of the image.
Differently colored light-emitting units may have different operating characteristics. For instance, the red, green, and blue light-emitting units may emit light at different intensities. In addition, the scanning device may sense the different colors in the color space differently. Thus, even if the red, green, and blue light-emitting units emit light at equal intensities, the scanning device may sense the different colored light differently, such that the measured intensities are not equal.